I. Field of the Invention
This invention relates to an air cleaner which collects small dusts or particles in the air.
II. Description of the Prior Art
Conventional air cleaners include filter type air cleaners and electrostatic type air cleaners. Both types include a fan to inhale ambient air into the body of the cleaner to catch the dust in the air with a filter or an electrode. However, in those air cleaners using a fan, noise is generated by the fan. If the revolution of the fan is decreased to reduce the noise, the dust-collecting capacity of the air cleaner is also reduced accordingly.
An air cleaner which does not include a fan has been developed. This air cleaner utilizes the "corona discharge" phenomenon. This air cleaner includes a cathode and an anode, and a high voltage is applied to the electrodes. Electrons are emitted from the cathode to give the dust or other particles in the air negative charge. The negatively charged dust or particles are attracted to the anode and trapped by the anode, thus removing the dust or particles in the air. Since the negatively charged dust or particles flow from the cathode to the anode, an air flow which is so called "ion wind" is generated. In the conventional air cleaner of this type, the cathode and the anode are so arranged as to face each other. Thus, the ion wind blows in one direction, i.e., from the cathode to the anode. With this arrangement, if the air cleaner is placed along a wall (this type of air cleaner is usually placed along a wall), the air flow entering the air cleaner flows substantially parallel to the wall, thus staining the wall because the air flow entering the air cleaner contains dust or particles. Further, with this arrangement, the lines of electric force are substantially linear, i.e., they are generated from the cathode to the anode in substantially linear shape. Therefore, the air cleaner can collect the dust in only a limited area, and so the air-collecting power of the air cleaner is not satisfactory.